shibsp/handler/impl/SAML2Consumer.cpp

   1 /**
   2  * Licensed to the University Corporation for Advanced Internet
   3  * Development, Inc. (UCAID) under one or more contributor license
   4  * agreements. See the NOTICE file distributed with this work for
   5  * additional information regarding copyright ownership.
   6  *
   7  * UCAID licenses this file to you under the Apache License,
   8  * Version 2.0 (the "License"); you may not use this file except
   9  * in compliance with the License. You may obtain a copy of the
  10  * License at
  11  *
  12  * http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing,
  15  * software distributed under the License is distributed on an
  16  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
  17  * either express or implied. See the License for the specific
  18  * language governing permissions and limitations under the License.
  19  */
  20
  21 /**
  22  * SAML2Consumer.cpp
  23  *
  24  * SAML 2.0 assertion consumer service.
  25  */
  26
  27 #include "internal.h"
  28 #include "handler/AssertionConsumerService.h"
  29
  30 #ifndef SHIBSP_LITE
  31 # include "Application.h"
  32 # include "ServiceProvider.h"
  33 # include "SessionCache.h"
  34 # include "attribute/resolver/ResolutionContext.h"
  35 # include <saml/exceptions.h>
  36 # include <saml/SAMLConfig.h>
  37 # include <saml/binding/SecurityPolicyRule.h>
  38 # include <saml/saml2/core/Protocols.h>
  39 # include <saml/saml2/metadata/Metadata.h>
  40 # include <saml/saml2/metadata/MetadataCredentialCriteria.h>
  41 # include <saml/saml2/profile/SAML2AssertionPolicy.h>
  42 # include <xmltooling/XMLToolingConfig.h>
  43 # include <xmltooling/io/HTTPRequest.h>
  44 # include <xmltooling/util/DateTime.h>
  45 using namespace opensaml::saml2;
  46 using namespace opensaml::saml2p;
  47 using namespace opensaml::saml2md;
  48 using namespace opensaml;
  49 # ifndef min
  50 #  define min(a,b)            (((a) < (b)) ? (a) : (b))
  51 # endif
  52 #else
  53 # include "lite/SAMLConstants.h"
  54 #endif
  55
  56 using namespace shibsp;
  57 using namespace xmltooling;
  58 using namespace std;
  59
  60 namespace shibsp {
  61
  62 #if defined (_MSC_VER)
  63     #pragma warning( push )
  64     #pragma warning( disable : 4250 )
  65 #endif
  66
  67     class SHIBSP_DLLLOCAL SAML2Consumer : public AssertionConsumerService
  68     {
  69     public:
  70         SAML2Consumer(const DOMElement* e, const char* appId)
  71             : AssertionConsumerService(e, appId, Category::getInstance(SHIBSP_LOGCAT".SSO.SAML2")) {
  72 #ifndef SHIBSP_LITE
  73             m_ssoRule = nullptr;
  74             if (SPConfig::getConfig().isEnabled(SPConfig::OutOfProcess))
  75                 m_ssoRule = SAMLConfig::getConfig().SecurityPolicyRuleManager.newPlugin(BEARER_POLICY_RULE, e);
  76 #endif
  77         }
  78         virtual ~SAML2Consumer() {
  79 #ifndef SHIBSP_LITE
  80             delete m_ssoRule;
  81 #endif
  82         }
  83
  84 #ifndef SHIBSP_LITE
  85         void generateMetadata(SPSSODescriptor& role, const char* handlerURL) const {
  86             AssertionConsumerService::generateMetadata(role, handlerURL);
  87             role.addSupport(samlconstants::SAML20P_NS);
  88         }
  89
  90     private:
  91         void implementProtocol(
  92             const Application& application,
  93             const HTTPRequest& httpRequest,
  94             HTTPResponse& httpResponse,
  95             SecurityPolicy& policy,
  96             const PropertySet*,
  97             const XMLObject& xmlObject
  98             ) const;
  99
 100         SecurityPolicyRule* m_ssoRule;
 101 #else
 102         const XMLCh* getProtocolFamily() const {
 103             return samlconstants::SAML20P_NS;
 104         }
 105 #endif
 106     };
 107
 108 #if defined (_MSC_VER)
 109     #pragma warning( pop )
 110 #endif
 111
 112     Handler* SHIBSP_DLLLOCAL SAML2ConsumerFactory(const pair<const DOMElement*,const char*>& p)
 113     {
 114         return new SAML2Consumer(p.first, p.second);
 115     }
 116
 117 #ifndef SHIBSP_LITE
 118     class SHIBSP_DLLLOCAL _rulenamed : std::unary_function<const SecurityPolicyRule*,bool>
 119     {
 120     public:
 121         _rulenamed(const char* name) : m_name(name) {}
 122         bool operator()(const SecurityPolicyRule* rule) const {
 123             return rule ? !strcmp(m_name, rule->getType()) : false;
 124         }
 125     private:
 126         const char* m_name;
 127     };
 128 #endif
 129 };
 130
 131 #ifndef SHIBSP_LITE
 132
 133 void SAML2Consumer::implementProtocol(
 134     const Application& application,
 135     const HTTPRequest& httpRequest,
 136     HTTPResponse& httpResponse,
 137     SecurityPolicy& policy,
 138     const PropertySet*,
 139     const XMLObject& xmlObject
 140     ) const
 141 {
 142     // Implementation of SAML 2.0 SSO profile(s).
 143     m_log.debug("processing message against SAML 2.0 SSO profile");
 144
 145     // Remember whether we already established trust.
 146     // None of the SAML 2 bindings require security at the protocol layer.
 147     bool alreadySecured = policy.isAuthenticated();
 148
 149     // Check for errors...this will throw if it's not a successful message.
 150     checkError(&xmlObject, policy.getIssuerMetadata());
 151
 152     const Response* response = dynamic_cast<const Response*>(&xmlObject);
 153     if (!response)
 154         throw FatalProfileException("Incoming message was not a samlp:Response.");
 155
 156     const vector<saml2::Assertion*>& assertions = response->getAssertions();
 157     const vector<saml2::EncryptedAssertion*>& encassertions = response->getEncryptedAssertions();
 158     if (assertions.empty() && encassertions.empty())
 159         throw FatalProfileException("Incoming message contained no SAML assertions.");
 160
 161     // Maintain list of "legit" tokens to feed to SP subsystems.
 162     const Subject* ssoSubject=nullptr;
 163     const AuthnStatement* ssoStatement=nullptr;
 164     vector<const opensaml::Assertion*> tokens;
 165
 166     // Also track "bad" tokens that we'll cache but not use.
 167     // This is necessary because there may be valid tokens not aimed at us.
 168     vector<const opensaml::Assertion*> badtokens;
 169
 170     // And also track "owned" tokens that we decrypt here.
 171     vector<saml2::Assertion*> ownedtokens;
 172
 173     // With this flag on, we ignore any unsigned assertions.
 174     const EntityDescriptor* entity = nullptr;
 175     pair<bool,bool> flag = make_pair(false,false);
 176     if (alreadySecured && policy.getIssuerMetadata()) {
 177         entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 178         flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 179     }
 180
 181     // authnskew allows rejection of SSO if AuthnInstant is too old.
 182     const PropertySet* sessionProps = application.getPropertySet("Sessions");
 183     pair<bool,unsigned int> authnskew = sessionProps ? sessionProps->getUnsignedInt("maxTimeSinceAuthn") : pair<bool,unsigned int>(false,0);
 184
 185     // Saves off error messages potentially helpful for users.
 186     string contextualError;
 187
 188     // Ensure the Bearer rule is in the policy set.
 189     if (find_if(policy.getRules(), _rulenamed(BEARER_POLICY_RULE)) == nullptr)
 190         policy.getRules().push_back(m_ssoRule);
 191
 192     // Populate recipient as audience.
 193     policy.getAudiences().push_back(application.getRelyingParty(entity)->getXMLString("entityID").second);
 194
 195     time_t now = time(nullptr);
 196     for (vector<saml2::Assertion*>::const_iterator a = assertions.begin(); a!=assertions.end(); ++a) {
 197         try {
 198             // Skip unsigned assertion?
 199             if (!(*a)->getSignature() && flag.first && flag.second)
 200                 throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 201
 202             // We clear the security flag, so we can tell whether the token was secured on its own.
 203             policy.setAuthenticated(false);
 204             policy.reset(true);
 205
 206             // Extract message bits and re-verify Issuer information.
 207             extractMessageDetails(*(*a), samlconstants::SAML20P_NS, policy);
 208
 209             // Run the policy over the assertion. Handles replay, freshness, and
 210             // signature verification, assuming the relevant rules are configured,
 211             // along with condition and profile enforcement.
 212             policy.evaluate(*(*a), &httpRequest);
 213
 214             // If no security is in place now, we kick it.
 215             if (!alreadySecured && !policy.isAuthenticated())
 216                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 217
 218             // If we hadn't established Issuer yet, redo the signedAssertions check.
 219             if (!entity && policy.getIssuerMetadata()) {
 220                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 221                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 222                 if (!(*a)->getSignature() && flag.first && flag.second)
 223                     throw SecurityPolicyException("The incoming assertion was unsigned, violating local security policy.");
 224             }
 225
 226             // Address checking.
 227             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 228                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 229                 );
 230             if (subcondata && subcondata->getAddress()) {
 231                 auto_ptr_char boundip(subcondata->getAddress());
 232                 checkAddress(application, httpRequest, boundip.get());
 233             }
 234
 235             // Track it as a valid token.
 236             tokens.push_back(*a);
 237
 238             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 239             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(*a)->getAuthnStatements();
 240             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 241                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 242                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 243                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 244                     ssoStatement = *s;
 245             }
 246
 247             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 248             if (!ssoSubject || (!ssoSubject->getNameID() && (*a)->getSubject()->getNameID()))
 249                 ssoSubject = (*a)->getSubject();
 250         }
 251         catch (exception& ex) {
 252             m_log.warn("detected a problem with assertion: %s", ex.what());
 253             if (!ssoStatement)
 254                 contextualError = ex.what();
 255             badtokens.push_back(*a);
 256         }
 257     }
 258
 259     // In case we need decryption...
 260     CredentialResolver* cr=application.getCredentialResolver();
 261     if (!cr && !encassertions.empty())
 262         m_log.warn("found encrypted assertions, but no CredentialResolver was available");
 263
 264     for (vector<saml2::EncryptedAssertion*>::const_iterator ea = encassertions.begin(); cr && ea!=encassertions.end(); ++ea) {
 265         // Attempt to decrypt it.
 266         saml2::Assertion* decrypted=nullptr;
 267         try {
 268             Locker credlocker(cr);
 269             auto_ptr<MetadataCredentialCriteria> mcc(
 270                 policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 271                 );
 272             auto_ptr<XMLObject> wrapper((*ea)->decrypt(*cr, application.getRelyingParty(entity)->getXMLString("entityID").second, mcc.get()));
 273             decrypted = dynamic_cast<saml2::Assertion*>(wrapper.get());
 274             if (decrypted) {
 275                 wrapper.release();
 276                 ownedtokens.push_back(decrypted);
 277                 if (m_log.isDebugEnabled())
 278                     m_log.debugStream() << "decrypted Assertion: " << *decrypted << logging::eol;
 279             }
 280         }
 281         catch (exception& ex) {
 282             m_log.error(ex.what());
 283         }
 284         if (!decrypted)
 285             continue;
 286
 287         try {
 288             // We clear the security flag, so we can tell whether the token was secured on its own.
 289             policy.setAuthenticated(false);
 290             policy.reset(true);
 291
 292             // Extract message bits and re-verify Issuer information.
 293             extractMessageDetails(*decrypted, samlconstants::SAML20P_NS, policy);
 294
 295             // Run the policy over the assertion. Handles replay, freshness, and
 296             // signature verification, assuming the relevant rules are configured,
 297             // along with condition and profile enforcement.
 298             // We have to marshall the object first to ensure signatures can be checked.
 299             if (!decrypted->getDOM())
 300                 decrypted->marshall();
 301             policy.evaluate(*decrypted, &httpRequest);
 302
 303             // If no security is in place now, we kick it.
 304             if (!alreadySecured && !policy.isAuthenticated())
 305                 throw SecurityPolicyException("Unable to establish security of incoming assertion.");
 306
 307             // If we hadn't established Issuer yet, redo the signedAssertions check.
 308             if (!entity && policy.getIssuerMetadata()) {
 309                 entity = dynamic_cast<const EntityDescriptor*>(policy.getIssuerMetadata()->getParent());
 310                 flag = application.getRelyingParty(entity)->getBool("requireSignedAssertions");
 311                 if (!decrypted->getSignature() && flag.first && flag.second)
 312                     throw SecurityPolicyException("The decrypted assertion was unsigned, violating local security policy.");
 313             }
 314
 315             // Address checking.
 316             SubjectConfirmationData* subcondata = dynamic_cast<SubjectConfirmationData*>(
 317                 dynamic_cast<SAML2AssertionPolicy&>(policy).getSubjectConfirmation()->getSubjectConfirmationData()
 318                 );
 319             if (subcondata && subcondata->getAddress()) {
 320                 auto_ptr_char boundip(subcondata->getAddress());
 321                 checkAddress(application, httpRequest, boundip.get());
 322             }
 323
 324             // Track it as a valid token.
 325             tokens.push_back(decrypted);
 326
 327             // Save off the first valid SSO statement, but favor the "soonest" session expiration.
 328             const vector<AuthnStatement*>& statements = const_cast<const saml2::Assertion*>(decrypted)->getAuthnStatements();
 329             for (vector<AuthnStatement*>::const_iterator s = statements.begin(); s!=statements.end(); ++s) {
 330                 if (authnskew.first && authnskew.second && (*s)->getAuthnInstant() && (now - (*s)->getAuthnInstantEpoch() > authnskew.second))
 331                     contextualError = "The gap between now and the time you logged into your identity provider exceeds the limit.";
 332                 else if (!ssoStatement || (*s)->getSessionNotOnOrAfterEpoch() < ssoStatement->getSessionNotOnOrAfterEpoch())
 333                     ssoStatement = *s;
 334             }
 335
 336             // Save off the first valid Subject, but favor an unencrypted NameID over anything else.
 337             if (!ssoSubject || (!ssoSubject->getNameID() && decrypted->getSubject()->getNameID()))
 338                 ssoSubject = decrypted->getSubject();
 339         }
 340         catch (exception& ex) {
 341             m_log.warn("detected a problem with assertion: %s", ex.what());
 342             if (!ssoStatement)
 343                 contextualError = ex.what();
 344             badtokens.push_back(decrypted);
 345         }
 346     }
 347
 348     if (!ssoStatement) {
 349         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 350         if (contextualError.empty())
 351             throw FatalProfileException("A valid authentication statement was not found in the incoming message.");
 352         throw FatalProfileException(contextualError.c_str());
 353     }
 354
 355     // May need to decrypt NameID.
 356     bool ownedName = false;
 357     NameID* ssoName = ssoSubject->getNameID();
 358     if (!ssoName) {
 359         EncryptedID* encname = ssoSubject->getEncryptedID();
 360         if (encname) {
 361             if (!cr)
 362                 m_log.warn("found encrypted NameID, but no decryption credential was available");
 363             else {
 364                 Locker credlocker(cr);
 365                 auto_ptr<MetadataCredentialCriteria> mcc(
 366                     policy.getIssuerMetadata() ? new MetadataCredentialCriteria(*policy.getIssuerMetadata()) : nullptr
 367                     );
 368                 try {
 369                     auto_ptr<XMLObject> decryptedID(encname->decrypt(*cr,application.getRelyingParty(entity)->getXMLString("entityID").second,mcc.get()));
 370                     ssoName = dynamic_cast<NameID*>(decryptedID.get());
 371                     if (ssoName) {
 372                         ownedName = true;
 373                         decryptedID.release();
 374                         if (m_log.isDebugEnabled())
 375                             m_log.debugStream() << "decrypted NameID: " << *ssoName << logging::eol;
 376                     }
 377                 }
 378                 catch (exception& ex) {
 379                     m_log.error(ex.what());
 380                 }
 381             }
 382         }
 383     }
 384
 385     m_log.debug("SSO profile processing completed successfully");
 386
 387     // We've successfully "accepted" at least one SSO token, along with any additional valid tokens.
 388     // To complete processing, we need to extract and resolve attributes and then create the session.
 389
 390     // Now we have to extract the authentication details for session setup.
 391
 392     // Session expiration for SAML 2.0 is jointly IdP- and SP-driven.
 393     time_t sessionExp = ssoStatement->getSessionNotOnOrAfter() ?
 394         (ssoStatement->getSessionNotOnOrAfterEpoch() + XMLToolingConfig::getConfig().clock_skew_secs) : 0;
 395     pair<bool,unsigned int> lifetime = sessionProps ? sessionProps->getUnsignedInt("lifetime") : pair<bool,unsigned int>(true,28800);
 396     if (!lifetime.first || lifetime.second == 0)
 397         lifetime.second = 28800;
 398     if (sessionExp == 0)
 399         sessionExp = now + lifetime.second;     // IdP says nothing, calulate based on SP.
 400     else
 401         sessionExp = min(sessionExp, now + lifetime.second);    // Use the lowest.
 402
 403     const AuthnContext* authnContext = ssoStatement->getAuthnContext();
 404
 405     try {
 406         // The context will handle deleting attributes and new tokens.
 407         auto_ptr<ResolutionContext> ctx(
 408             resolveAttributes(
 409                 application,
 410                 policy.getIssuerMetadata(),
 411                 samlconstants::SAML20P_NS,
 412                 nullptr,
 413                 ssoName,
 414                 (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 415                 (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 416                 &tokens
 417                 )
 418             );
 419
 420         if (ctx.get()) {
 421             // Copy over any new tokens, but leave them in the context for cleanup.
 422             tokens.insert(tokens.end(), ctx->getResolvedAssertions().begin(), ctx->getResolvedAssertions().end());
 423         }
 424
 425         // Now merge in bad tokens for caching.
 426         tokens.insert(tokens.end(), badtokens.begin(), badtokens.end());
 427
 428         application.getServiceProvider().getSessionCache()->insert(
 429             application,
 430             httpRequest,
 431             httpResponse,
 432             sessionExp,
 433             entity,
 434             samlconstants::SAML20P_NS,
 435             ssoName,
 436             ssoStatement->getAuthnInstant() ? ssoStatement->getAuthnInstant()->getRawData() : nullptr,
 437             ssoStatement->getSessionIndex(),
 438             (authnContext && authnContext->getAuthnContextClassRef()) ? authnContext->getAuthnContextClassRef()->getReference() : nullptr,
 439             (authnContext && authnContext->getAuthnContextDeclRef()) ? authnContext->getAuthnContextDeclRef()->getReference() : nullptr,
 440             &tokens,
 441             ctx.get() ? &ctx->getResolvedAttributes() : nullptr
 442             );
 443
 444         if (ownedName)
 445             delete ssoName;
 446         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 447     }
 448     catch (exception&) {
 449         if (ownedName)
 450             delete ssoName;
 451         for_each(ownedtokens.begin(), ownedtokens.end(), xmltooling::cleanup<saml2::Assertion>());
 452         throw;
 453     }
 454 }
 455
 456 #endif